Merge pull request #565 from kavalerov/patch-1

Simplify upgrade section in the readme as currently it is talking about breaking changes in v1.2 (and there already was v2 with additional changes)

README.md

@@ -47,10 +47,9 @@ cd ably-python
 python setup.py install
 ```
 
-## Breaking API Changes in Version 1.2.0
+## Upgrade / Migration Guide
 
-Please see our [Upgrade / Migration Guide](UPDATING.md) for notes on changes you need to make to your code to update it to use the new API
-introduced by version 1.2.0.
+Please see our [Upgrade / Migration Guide](UPDATING.md) for notes on changes you need to make to your code to update it to use the new APIs when migrating from older versions.
 
 ## Usage